import { computed, reactive, toRefs } from 'vue'
import { Table } from './interface'

/**
 * @description table 页面操作方法封装
 * @param {Function} api 获取表格数据 api 方法 (必传)
 * @param {Object} initParam 获取数据初始化参数 (非必传，默认为{})
 * @param {Boolean} isPageable 是否有分页 (非必传，默认为true)
 * @param {Function} dataCallBack 对后台返回的数据进行处理的方法 (非必传)
 * */
export const useTable = (
  api?: (params: any) => Promise<any>,
  initParam: object = {},
  isPageable: boolean = true,
  spanMethod: boolean = false,
  dataCallBack?: (data: any) => any,
  requestError?: (error: any) => void,
  mergerFields?: any
) => {
  const state = reactive<Table.StateProps>({
    // 表格数据
    tableData: [],
    // 分页数据
    pageable: {
      // 当前页数
      pageNum: 1,
      // 每页显示条数
      pageSize: 20,
      // 总条数
      total: 0,
    },
    // 查询参数(只包括查询)
    searchParam: {},
    // 初始化默认的查询参数
    searchInitParam: {},
    // 总参数(包含分页和查询参数)
    totalParam: {},
  })

  /**
   * @description 分页查询参数(只包括分页和表格字段排序,其他排序方式可自行配置)
   * */
  const pageParam = computed({
    get: () => {
      return {
        pageNum: state.pageable.pageNum,
        pageSize: state.pageable.pageSize,
      }
    },
    set: (newVal: any) => {
      console.log('我是分页更新之后的值', newVal)
    },
  })

  /**
   * @description 获取表格数据
   * @return void
   * */
  const getTableList = async () => {
    if (!api) return
    try {
      // 先把初始化参数和分页参数放到总参数里面
      Object.assign(state.totalParam, initParam, isPageable ? pageParam.value : {})
      let { data } = await api({ ...state.searchInitParam, ...state.totalParam })
      dataCallBack && (data = dataCallBack(data))
      state.tableData = isPageable ? data.list : data.list || data
      if (spanMethod) {
        setTabelRowSpan(state.tableData, mergerFields == null ? ['id', 'operation'] : ['id', 'operation', ...mergerFields])
      }

      // 解构后台返回的分页数据 (如果有分页更新分页信息)
      if (isPageable) {
        const { pageNum, pageSize, total } = data
        updatePageable({ pageNum, pageSize, total })
      }
    } catch (error) {
      requestError && requestError(error)
    }
  }

  /**
   * @description 更新查询参数
   * @return void
   * */
  const updatedTotalParam = () => {
    state.totalParam = {}
    // 处理查询参数，可以给查询参数加自定义前缀操作
    let nowSearchParam: Table.StateProps['searchParam'] = {}
    // 防止手动清空输入框携带参数（这里可以自定义查询参数前缀）
    for (let key in state.searchParam) {
      // * 某些情况下参数为 false/0 也应该携带参数
      if (state.searchParam[key] || state.searchParam[key] === false || state.searchParam[key] === 0) {
        nowSearchParam[key] = state.searchParam[key]
      }
    }
    Object.assign(state.totalParam, nowSearchParam, isPageable ? pageParam.value : {})
  }

  /**
   * @description 更新分页信息
   * @param {Object} pageable 后台返回的分页数据
   * @return void
   * */
  const updatePageable = (pageable: Table.Pageable) => {
    Object.assign(state.pageable, pageable)
  }

  /**
   * @description 表格数据查询
   * @return void
   * */
  const search = () => {
    state.pageable.pageNum = 1
    updatedTotalParam()
    getTableList()
  }

  /**
   * @description 表格数据重置
   * @return void
   * */
  const reset = () => {
    state.pageable.pageNum = 1
    state.searchParam = {}
    // 重置搜索表单的时，如果有默认搜索参数，则重置默认的搜索参数
    Object.keys(state.searchInitParam).forEach((key) => {
      state.searchParam[key] = state.searchInitParam[key]
    })
    updatedTotalParam()
    getTableList()
  }

  /**
   * @description 每页条数改变
   * @param {Number} val 当前条数
   * @return void
   * */
  const handleSizeChange = (val: number) => {
    state.pageable.pageNum = 1
    state.pageable.pageSize = val
    getTableList()
  }

  /**
   * @description 当前页改变
   * @param {Number} val 当前页
   * @return void
   * */
  const handleCurrentChange = (val: number) => {
    state.pageable.pageNum = val
    getTableList()
  }

  //存储合并单元格的开始位置
  type TableDataItem = {
    [key: string]: any
    mergeCell?: any[]
  }

  type EffectMergeItem = {
    [key: string]: string[]
  }

  const setTabelRowSpan = (tableData: TableDataItem[], fieldArr: string[], effectMerge: EffectMergeItem = {}) => {
    let lastItem: TableDataItem = {}

    fieldArr.forEach((field: string, index: number) => {
      let judgeArr: string[] = fieldArr.slice(0, index + 1)

      if (effectMerge[field]) {
        judgeArr = [...effectMerge[field], field]
      }

      tableData.forEach((item: TableDataItem) => {
        item.mergeCell = fieldArr
        const rowSpan = `rowspan_${field}`
        if (judgeArr.every((e: string) => lastItem[e] === item[e] && item[e] !== '')) {
          item[rowSpan] = 0
          lastItem[rowSpan] += 1
        } else {
          item[rowSpan] = 1
          lastItem = item
        }
      })
    })
  }

  return {
    ...toRefs(state),
    getTableList,
    search,
    reset,
    handleSizeChange,
    handleCurrentChange,
    updatedTotalParam,
  }
}
